From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx118.postini.com [74.125.245.118]) by kanga.kvack.org (Postfix) with SMTP id A1B986B0044 for ; Thu, 23 Aug 2012 05:50:25 -0400 (EDT) Date: Thu, 23 Aug 2012 11:50:22 +0200 From: Michal Hocko Subject: Re: Fixup the page of buddy_higher address's calculation Message-ID: <20120823095022.GB10685@dhcp22.suse.cz> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Li Haifeng Cc: Andrew Morton , Mel Gorman , Minchan Kim , Johannes Weiner , linux-mm@kvack.org, linux-kernel@vger.kernel.org On Thu 23-08-12 16:40:13, Li Haifeng wrote: > From d7cd78f9d71a5c9ddeed02724558096f0bb4508a Mon Sep 17 00:00:00 2001 > From: Haifeng Li > Date: Thu, 23 Aug 2012 16:27:19 +0800 > Subject: [PATCH] Fixup the page of buddy_higher address's calculation Some general questions: Any word about the change? Is it really that obvious? Why do you think the current state is incorrect? How did you find out? And more specific below: > Signed-off-by: Haifeng Li > --- > mm/page_alloc.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index ddbc17d..5588f68 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -579,7 +579,7 @@ static inline void __free_one_page(struct page *page, > combined_idx = buddy_idx & page_idx; > higher_page = page + (combined_idx - page_idx); > buddy_idx = __find_buddy_index(combined_idx, order + 1); > - higher_buddy = page + (buddy_idx - combined_idx); > + higher_buddy = page + (buddy_idx - page_idx); We are finding buddy index for combined_idx so why should we use page_idx here? > if (page_is_buddy(higher_page, higher_buddy, order + 1)) { > list_add_tail(&page->lru, > &zone->free_area[order].free_list[migratetype]); > -- > 1.7.5.4 -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org